This project is a continuation of a long-range program of research concerned with investigating the effects of drugs and other treatments on memory storage processes. The primary objective is to contribute to an understanding of the neurobiological bases of memory storage. The basic assumption underlying the research is that the neurobiological processes of memory storage are initially labile following a training experience, and they remain susceptible to modulating influences--either facilitation or impairment--for a period of time after training. The proposed experiments are based on evidence that peripherally acting neurohumors play a role in the modulation of memory storage processes. Specifically, we have obtained evidence that adrenal medullary catecholamines, which act on peripheral adrenergic end organ receptors, may be of particular importance for memory storage. To investigate this hypothesis, we will examine the role of the adrenal medullae and the sympathetic nervous system in mediating the memory facilitation produced by 4-OH amphetamine and epinephrine, two peripherally acting agents that increase catecholaminergic neurotransmission. Following this, we will investigate the hypothesis that peripherally acting peptides that influence memory, such as ACTH and the enkephalins, do so by acting on peripheral catecholamine systems. Finally, we will study the relationship between peripheral catecholamines and agents that modulate memory through central actions. This research will provide information about the ways that transient peripheral events influence the induction of long-lasting CNS alterations that provide the basis for memory storage.